1. Field of the Invention
The present invention relates to an electrostatic relay using a plurality of electrets which generate a strong electrostatic force for precisely and rapidly operating the relay.
2. Description of the Prior Art
Prior electrostatic relays using an electret do not have enough electrostatic force to move a movable element of the relay. For example, an electrostatic relay as described in U.S. Pat. No. 4,078,183 comprises two control electrodes between which is positioned a movable electret. The lower part of the movable electret is clampled as a cantilever by insulating shims, so that the movable electret can be moved between a position close to the electrode and a position close to the other electrode. Each of movable conductors is placed at the upper end of respective surface of the movable electrode. Two fixed conductors are arranged on the electrodes, respectively. The movable conductor can be contacted with the fixed conductors on the electrode by an electrostatic force which is generated by an impressed voltage between the electrode and the movable electret. The other movable conductor can be contacted with the fixed conductors on the other electrode by an electrostatic force which is generated by an impressed voltage between the other electrode and the movable electret. However, it is so difficult for the prior electrostatic relay to perform a monostable operation and also to obtain enough electrostatic force in order to move the movable electret. Therefore, the relay does not have enough electrostatic force for rapidly and precisely operating the relay.